At the present time a number of different lighting sources are utilized for eye surgical operations. However, some of these light sources are not suitable for retinal operations as they do not provide sufficient light to the back of the eyeball. In addition, some of the light sources require the eye surgeon to physically hold a light probe, which uses one of his hands and leaves only one hand free for manipulating surgical instruments.
One type of surgical technique involves the use of a suitable fluid, such as saline solution, silicon oil or a gas, which is injected into the eyeball during a surgical procedure to maintain the eyeball in an inflated state. This technique is called "infusion" and requires a source of fluid, a tube (infusion cannula) leading from the source and a needle cannula connected to the tube and used to inject the fluid into the eyeball. The needle must generally be retained in place during the operation so that the fluid may be constantly replenished.
Often, in the case of retinal surgery (vitrectomy surgery) it is desired that the light source be within the eyeball (within the globe) in the form of an internal light (endoillumination). This permits the direct light of the operating microscope to be turned off and reduces glare at the cornea and corneal contact lens surfaces.
A presently commercially available system for vitro-retinal surgery combining illumination and infusion is the "DPS 100" (TM), from Storz Instrument GmbH, Im Schuhmachergewann 4, D-6900 Heidelberg 1, Germany ("Storz system"). In the Storz system three incisions are made in the eye, each 2.8 mm in length, which allows insertion therethrough of three illuminated pilot tubes each having an outer diameter of 1.65 mm (16 ga.) and an inner bore diameter of 0.9 mm (20 gs.). It is a multiport illumination system having three pilot tubes. The tubes are connected near their ends to plates which are sutured to the pars plana. Very thin instruments, of 20 gauge or less, may be inserted and manipulated through the tubes. A bunch of hair-thin optical fibers are formed, within the pilot tube, into an optical fiber tube whose bore forms the inner diameter of the pilot tube. Each of the tubes transmits light through its bundle of optical fibers and transmits infusion fluids, such as silicon oil, through its bore.
There are a number of disadvantages to the Storz system. First, and primarily, it requires three large incisions, each of 2.8 mm in length, and requires the insertion of three relatively large diameter pilot tubes through the incisions. The number and size of those cuts may be a serious problem in many surgical procedures. Secondly, some surgeons do not wish to be limited to using instruments which fit through the pilot tubes, i.e., instruments of less than 20 gauge.
An article entitled "A New Endoillumination Infusion Cannula For Pars Plana Vitrectomy" by K. Zinn, A. Grinblat, H. Katzin, M. Epstein and C. Kot, Ophthalmic Surgery, Vol. 11, No. 12, Dec. 1980, pgs. 850-854, incorporated by reference herein, describes a combined illumination and infusion system, which was not manufactured commercially. The infusion cannula (tube for infusion liquids) is within a bundle of optical fibers.